Controlled release pharmaceutical compositions of pregabalin

ABSTRACT

A controlled release pharmaceutical composition which comprises therapeutically effective amount of pregabalin or salts thereof as active ingredient, a hydrophobic release controlling agent(s) and optionally other pharmaceutically acceptable excipients thereof.

This application is a divisional of U.S. patent application Ser. No.12/744,477, now U.S. Pat. No. 8,454,993 which was a national stagefiling and claims the priority benefit of PCT/IN2008/000770 filed 14Nov. 2008, and also claims the benefit of priority from provisionalIndian patent application ser. no. 1593/KOL/2007, which was filed on 23Nov. 2007.

FIELD OF THE INVENTION

The present invention relates to controlled release pharmaceuticalcompositions comprising pregabalin or salts thereof using hydrophobicrate controlling components.

BACKGROUND OF THE INVENTION

Pregabalin is an analog of gamma-aminobutyric acid (GABA). It is usefulas antiseizure therapy for central nervous system disorders such asepilepsy, Huntington's chorea, cerebral ischemia, Parkinson's disease,tardive dyskinesia, and spasticity.

Pregabalin or (S)-(+)-3-(amino methyl)-5-methylhexanoic acid, binds tothe alpha-2-delta (α-δ) subunit of a calcium channel and is related tothe endogenous inhibitory neurotransmitter [γ] amino butyric acid(GABA), which is involved in the regulation of brain neuronal activity.Pregabalin exhibits anti-seizure activity and is useful for treating,among other conditions, epilepsy, pain, physiological conditionsassociated with psychomotor stimulants, inflammation, gastrointestinaldamage, alcoholism, insomnia, fibromyalgia, and various psychiatricdisorders, including anxiety, depression, mania, and bipolar disorder.Pregabalin was approved in the United States on Dec. 30, 2004, animmediate release dosage form for use in the treatment of diabeticperipheral neuropathy, postherpetic neuralgia, and as an adjunctivetreatment for partial onset seizures in adults.

Pregabalin is currently available as immediate release Lyrica® in 25,50, 75, 100, 150, 200, 225, and 300 mg hard shell capsules and isadministered in patients two or three times daily (BID or TID).

The recommended dose of pregabalin is 100 mg three times a day (300mg/day) for the treatment of neuropathic pain associated with diabeticperipheral neuropathy and post herpetic neuralgia. Pregabalin at dosesof 150 to 600 mg/day is recommended for adjunctive therapy for adultpatients with partial onset seizures.

To maintain reasonably stable plasma concentrations, it is necessary toresort to frequent dosing, and the resulting inconvenience to thepatient often results in lowered compliance with the prescribed dosingregimen. Moreover, widely fluctuating plasma concentrations of the drugmay result in administration of less than therapeutic amounts of thedrug in a conservative dosing regimen, or amounts too large for theparticular patient in an aggressive dosing regimen.

This type of multiple administrations leads to substantial fluctuationsin the plasma concentration of the drug, especially in chronicadministration.

The convenience of once daily dosing generally improves patientcompliance, especially for elderly patients and for patients takingmultiple medications. Once per day dosing may also lessen or preventpotentially undesirable dose-related effects by reducing peak bloodlevels (C_(max)) and may also increase drug efficacy by increasingminimum plasma concentrations (C_(min)).

Once daily dosing of pregabalin, however, presents numerous challengesas pregabalin is not absorbed uniformly in the gastrointestinal (Gl)tract. Pregabalin is absorbed in the small intestine and in theascending colon in humans.

Various approaches have been tried out for developing a once dailydosage form of pregabalin.

WO 2007/052125 A2 relates to a pharmaceutical composition comprisingpregabalin, and matrix forming agent and a swelling agent, thematrix-forming agent comprising polyvinyl acetate andpolyvinylpyrrolidone, and the swelling agent comprising cross-linkedpolyvinylpyrrolidone, wherein the pharmaceutical composition is adaptedfor once-daily oral dosing.

US 2005/0163848 A1 relates to a complex comprised of pregabalin and atransport moiety, such as an alkyl sulfate. The complex has an enhancedabsorption in the gastrointestinal tract, particularly the lowergastrointestinal tract. The complex, and compositions and dosage formsprepared using the complex, provide for absorption by the body of thedrug through a period of ten to twenty-four hours, thus enabling aonce-daily dosage form for pregabalin.

US 2002/0119197 A1 relates to pharmaceutical dosage form comprising acentral core including a pharmaceutical agent in a controlled-releasecomposition, said core having two exposed opposite end surfaces and aperipheral surface at an outer edge of said core extending between saidtwo opposed end surfaces, said peripheral edge surrounded by adiffusion-limiting sleeve, wherein said sleeve limits the diffusion offluids into said core.

Pregabalin is a white to off-white, crystalline solid with a pK_(a1) of4.2 and a pK_(a2) of 10.6. It is freely soluble in water and both basicand acidic aqueous solutions.

Most of the above-mentioned patent applications disclose controlleddelivery systems, which utilize hydrophilic, polymeric matrices.However, for highly soluble drugs, such matrices do not provide adequatecontrol over the drug release rate, instead resulting in a release thatapproximates first-order kinetics.

Thus there is need to develop stable controlled release compositions ofpregabalin, which provide complete drug release and afford stable plasmalevels in a once-a-day dosing regimen using hydrophobic releasecontrolling agent(s).

A further aspect of the invention provides a solid dosage form, such asa tablet, capsules pellets, granules, powders and microtablets that areadapted for once daily oral dosing.

OBJECT OF THE INVENTION

The controlled release pharmaceutical compositions comprising pregabalinof present invention may employ any pharmaceutically acceptable form ofpregabalin including base or its pharmaceutically acceptable complexes,salts, polymorphs, hydrates, solvates, enantiomers or racemates.

Therefore, the first object of the present invention provides acontrolled release pharmaceutical compositions comprisingtherapeutically effective amount of pregabalin or pharmaceuticallyacceptable complexes, salts, polymorphs, hydrates, solvates, enantiomersor racemates thereof wherein the composition comprises pregabalin andhydrophobic release controlling agent(s), and optionally otherpharmaceutically acceptable excipients.

Yet another object of the present invention provides a controlledrelease pharmaceutical compositions comprising therapeutically effectiveamount of pregabalin or pharmaceutically acceptable complexes, salts,polymorphs, hydrates, solvates, enantiomers or racemates thereof whereinthe composition comprises pregabalin and hydrophobic release controllingagent(s), and optionally a wicking agent.

Yet another object of the present invention provides a controlledrelease pharmaceutical compositions comprising therapeutically effectiveamount of pregabalin or pharmaceutically acceptable complexes, salts,polymorphs, hydrates, solvates, enantiomers or racemates thereof whereinthe composition comprises pregabalin and hydrophobic release controllingagent(s), optionally a wicking agent and additionally hydrophilic ratecontrolling components.

Yet another object of the invention provides controlled releasepharmaceutical compositions comprising pregabalin or pharmaceuticallyacceptable complexes, salts, polymorphs, hydrates, solvates, enantiomersor racemates thereof, comprising a core wherein said core comprisespregabalin or pharmaceutically acceptable complexes, salts, polymorphs,hydrates, solvates, enantiomers or racemates thereof, with one or moreauxiliary pharmaceutical excipients and a coating layer comprising ratecontrolling hydrophobic and hydrophilic agent(s).

Yet another object of the present invention is to provide for controlledrelease pharmaceutical compositions comprising therapeutically effectiveamount of pregabalin or pharmaceutically acceptable complexes, salts,polymorphs, hydrates, solvates, enantiomers or racemates thereof whereinthe composition comprises pregabalin and hydrophobic release controllingagent(s)thereof, in which the compositions exhibit in vitro release ofpregabalin not less than about 75% after 12 hours, especially not lessthan about 75% after 10 hours.

Yet another object of the present invention is to provide a controlledrelease pharmaceutical composition comprising therapeutically effectiveamount of pregabalin or pharmaceutically acceptable complexes, salts,polymorphs, hydrates, solvates, enantiomers or racemates thereof whereinthe composition comprises pregabalin and hydrophobic release controllingagent(s)thereof, in which the compositions exhibits in vitro release ofpregabalin not less than about 55%, after 7 hours.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a release profile of controlled release dosage forms ofpregabalin of example 1, in Type II USP apparatus, 0.1N HCl followed bypH 6.8 phosphate buffer, 900 ml, and 50 rpm.

FIG. 2 shows a release profile of controlled release dosage forms ofpregabalin of example 2, in Type II USP apparatus, 0.1N HCl followed bypH 6.8 phosphate buffer, 900 ml, and 50 rpm.

DETAILED DESCRIPTION OF THE INVENTION

The dosage forms of the present invention typically contain 25 to 900 mgpregabalin as base. The dosage forms of the invention optionally maycomprise pharmaceutically acceptable complexes, salts, polymorphs,hydrates, solvates, enantiomers or racemates of pregabalin.

“Pharmaceutical composition” refers to the combination of one or moredrug substances and one or more excipients.

“Drug product,” “pharmaceutical dosage form,” “dosage form,” “finaldosage form” and the like, refer to a pharmaceutical composition that isadministered to a subject in need of treatment and generally may be inthe form of tablets, capsules, sachets containing powder or granules,pellets, liquid solutions or suspensions, patches, and the like.

“About” will be understood by persons of ordinary skill in the art andwill vary to some extent on the context in which the term is used Ifthere are uses of the term which are not clear to persons of ordinaryskill in the art given the context in which it is used, “about” willmean up to plus or minus 10% of the particular term.

The term “controlled release compositions” herein refers to anycomposition or dosage form which comprises an active drug and which isformulated to provide a longer duration of pharmacological responseafter administration of the dosage form than is ordinarily experiencedafter administration of a corresponding immediate release compositioncomprising the same drug in the same amount. Controlled releasecompositions include, inter alia, those compositions described elsewhereas “extended release”, “delayed release”, “sustained release”,“prolonged release”, “programmed release”, “time release” and/or “ratecontrolled” compositions or dosage forms.

The term “wicking agent” is defined as any material with the ability todraw water into the network of a delivery dosage form. By so doing, awicking agent provides enhanced flow channels for the pharmaceuticalagent, which has been made predominantly into its solubilized form.

The hydrophobic release controlling agents are selected from but are notlimited to polyvinyl acetate dispersion, ethyl cellulose, celluloseacetate, cellulose propionate (lower, medium or higher molecularweight), cellulose acetate propionate, cellulose acetate butyrate,cellulose acetate phthalate, cellulose triacetate, poly (methylmethacrylate), poly (ethyl methacrylate), poly (butyl methacrylate),poly (isobutyl methacrylate), and poly (hexyl methacrylate), poly(isodecyl methacrylate), poly (lauryl methacrylate), poly (phenylmethacrylate), poly (methyl acrylate), poly (isopropyl acrylate), poly(isobutyl acrylate), poly (octadecyl acrylate), waxes such as beeswax,carnauba wax, paraffin wax, microcrystalline wax, and, ozokerite; fattyalcohols such as cetostearyl alcohol, stearyl alcohol, cetyl alcohol andmyristyl alcohol, and fatty acid esters such as glyceryl monostearate;glycerol monooleate, acetylated monoglycerides, tristearin, tripalmitin,cetyl esters wax, glyceryl palmitostearate, glyceryl behenate, zein andhydrogenated vegetable oils or their mixtures thereof.

The hydrophilic release controlling agents are selected from but are notlimited to hydroxypropyl methylcellulose (HPMC), hydroxypropyl cellulose(HPC), polyethylene oxide, polyvinyl alcohol, polyvinylpyrrolidone,xanthan gum, guar gum, chitosan and its derivatives, carbomer,carrageenan, carboxymethyl cellulose, sodium alginate, polyglycolizedglycerides, polyethyleneglycol, or mixture thereof.

The wicking agents are selected from the group comprising hydrophilic,organic, polymeric, fusible substance or a particulate soluble orinsoluble inorganic material. Suitable hydrophilic, organic, fusiblewicking agents include polyethylene glycols (PEGs) of various molecularweights e.g. 1,000 to 20,000 preferably 4,000 to 10,000 and suitableparticulate inorganic wicking agents include dicalcium phosphate andlactose. It is preferred to use a hydrophilic fusible, organic polymericas wicking agent. Other examples of wicking agents include high HLBsurfactants (for example Tween 20, Tween 60 or Tween 80; ethylene oxidepropylene oxide block copolymers, ionic surfactants such as sodiumlauryl sulfate, sodium docusate, non-swelling hydrophilic polymers suchas cellulose ethers, complexing agents such as: polyvinyl pyrrolidone,cyclodextrins and non-ionic surface active agents; and micelle formingagents, which may be surface active agents such as Tweens (Poly(ethylene Oxide) modified sorbitan monoesters), Spans (fatty acidsorbitan esters), sodium lauryl sulfate and sodium docusate.

The term “controlled release pharmaceutical compositions” includes apharmaceutical composition that encompasses one or more individualunits. The units may be a capsule or tablet or may be in form ofgranules, pellets, minitablets or beads.

The compositions of the present invention can also include othermaterials such as binders, diluents, anti-adherents, glidants andlubricants.

Diluents may be, for example, any pharmaceutically acceptable, non-toxicdiluent. Particular examples include lactose, dextrose, sucrose,maltose, microcrystalline cellulose, starch, calcium hydrogen phosphate,mannitol and the like.

Binders may be, for example, starch, sugars, gums, low molecular weighthydroxypropyl methylcellulose, povidone, hydroxypropyl cellulose,hydroxyethyl cellulose or the like.

Lubricants may be, for example, talc, magnesium stearate, calciumstearate, stearic acid, sodium stearyl fumarate, sodium benzoate or thelike.

Antiadherents and Glidants may be, for example, colloidal silicondioxide, talc or the like. Solid oral dosage forms of the presentinvention may be prepared by any conventional techniques for example drygranulation, direct compression, wet granulation, melt granulation andextrusion-spheronization.

EXAMPLES

The following examples are intended to be illustrative and non-limiting:

Example 1

Sr. No. Ingredient Mg/Unit dose CORE 1. Pregabalin 75.00 2.Microcrystalline Cellulose (Avicel PH 101) 73.00 3. HPMC E5 2.00 4.Purified Water Q.S. Total: 150.00 EXTENDED RELEASE COATING 1. EthylCellulose (N50) 9.80 2. HPMC E5 4.20 3. Triethyl Citrate 1.40 4. Talc4.60 5. Isopropyl Alcohol 80.00 6. Dichloromethane 320.00 Total Weight170.00 mg

Brief Manufacturing Procedure:

-   -   1. Mix Pregabalin with Microcrystalline Cellulose and sift them        through a suitable sieve and load the blend in RMG.    -   2. Prepare HPMC E5 solution in suitable quantity of water.    -   3. Granulate the blend of step 1 with binder solution of step 2.    -   4. Extrudate the wet mass through 1 mm sieve using extruder and        spheronize using spheronizer.    -   5. Dry the pellets at a suitable temperature in FBD and size        them to suitable fractions.    -   6. Disperse Ethyl cellulose, HPMC ES, Triethylcitrate and Talc        in the Isopropyl alcohol and Dichloromethane solution.    -   7. Coat pellets with the above coating composition in FBP to get        the build up of approximately in a range of 12-18% to get the        desired profile.    -   8. The coated pellets can either be filled in the capsules or        compressed as tablets.

Example 2

Sr. No. Ingredient Mg/Unit dose CORE 1. Pregabalin 75.00 2. HydrogenatedVegetable Oil 93.00 3. Magnesium Stearate 2.00 Total: 170.00 mg

Brief Manufacturing Procedure:

-   -   1) Mix Pregabalin and Hydrogenated Vegetable Oil material at        suitable temperature with continuous stiffing.    -   2) Maintain the temperature of the melt mass for a sufficient        period of time.    -   4) Sift the mass through a suitable sieve.    -   5) Store the final granules in a well-closed container.    -   6) These granules can either be filled in the capsules or        compressed as tablets.

Example 3

Sr. No. Ingredient Mg/Unit dose CORE 1. Pregabalin 150.00 2. Lactosemonohydrate 128.00 3. Ethylcellulose 40.00 4. Isopropyl Alcohol Q.S. 5.Colloidal silicon dioxide 11.60 6. Talc 6.40 7. Magnesium Stearate 4.008 Total Weight 340.00 mg

Brief Manufacturing Procedure:

-   -   1. Mix Pregabalin with Lactose monohydrate, Ethyl cellulose,        Colloidal silicon dioxide and Talc in a suitable blender.    -   2. Lubricate the blend with Magnesium stearate.    -   3. The above lubricated blend is compressed into tablets.

Example 4

Sr. No. Ingredient Mg/Capsule CORE 1. Pregabalin 75.00 2. Lactosemonohydrate 50.00 3. Starch 14.00 4. Purified Water Q.S. 5. Aerosil 4.006. Talc 4.00 7. Magnesium Stearate 3.00 Total 150.00 EXTENDED RELEASECOATING 1. Ethyl Cellulose (N50) 9.80 2. HPMC E5 4.20 3. TriethylCitrate 1.00 4. Talc 5.00 5. Isopropyl Alcohol 80.00 6. Dichloromethane320.00 Total Weight 170.00 mg

-   -   1. Mix Pregabalin with Lactose monohydrate, Starch and load the        blend in RMG.    -   2. Granulate the powder mass of step 1 with suitable quantity of        water.    -   3. Sift the above granulated mass through a suitable sieve.    -   4. Dry the granules in suitable dryer.    -   5. Lubricate the dried granules with aerosil, talc and magnesium        stearate.    -   6. Compress the above blend into minitablets or into a single        tablet.    -   7. Disperse Ethyl cellulose, HPMC ES, Triethylcitrate and Talc        in the Isopropyl alcohol and Dichloromethane solution.    -   8. Coat tablet or minitablet with the solution of step 7 to get        the build up of approximately in a range of 10-18% to get the        desired profile.    -   9. Alternatively the coated Minitablets can be filled into a        capsule of suitable size.

Example 5

Sr. No. Ingredient Mg/Capsule CORE 1. Pregabalin 75.00 2. Lactosemonohydrate 40.00 3. Starch 8.00 4. Microcrystalline cellulose 20.00 4.Aerosil 4.00 5. Magnesium Stearate 3.00 Total 150.00 EXTENDED RELEASECOATING 1. Ethyl Cellulose (N50) 9.80 2. HPMC E5 4.20 3. TriethylCitrate 1.00 4. Talc 5.00 5. Isopropyl Alcohol 80.00 6. Dichloromethane320.00 Total Weight 170.00 mg

-   -   1. Mix Pregabalin with Lactose monohydrate, Starch and        Microcrystalline cellulose    -   2. Lubricate the dried granules with aerosil and magnesium        stearate.    -   3. Compress the above blend into minitablets or into a single        tablet.    -   4. Disperse Ethyl cellulose, HPMC E5, Triethylcitrate and Talc        in the Isopropyl alcohol and Dichloromethane solution.    -   5. Coat tablet or minitablet with the coating solution of Step 4        to get the build up of approximately in a range of 12-18% to get        the desired profile.    -   6. Coated Minitablets can be filled into a capsule of suitable        size.

The invention claimed is:
 1. A controlled release pharmaceuticalcomposition comprising a therapeutically effective amount of pregabalinor salts thereof as active ingredient, a hydrophobic release controllingagent(s) additionally containing a wicking agent selected from the groupconsisting of a hydrophilic, organic, polymeric, fusible substance or aparticulate soluble or Particulate insoluble inorganic material.
 2. Acontrolled release pharmaceutical composition of claim 1 wherein thehydrophilic, organic, fusible wicking agent comprises polyethyleneglycols (PEGs) of various molecular weights from 1,000 to 20,000.
 3. Acontrolled release pharmaceutical composition of claim 1 wherein thewicking agent comprises dicalcium phosphate.
 4. A controlled releasepharmaceutical composition of claim 1 wherein the hydrophilic, organic,fusible wicking agent comprises polyethylene glycols (PEGs) of variousmolecular weights from 4,000 to 10,000.
 5. A controlled releasepharmaceutical composition of claim 1 wherein the wicking agentcomprises lactose.
 6. A controlled release pharmaceutical composition ofclaim 1 wherein the wicking agent consisting of a hydrophilic, organic,polymeric, fusible substance.